// ==++==
//
//   
//    Copyright (c) 2006 Microsoft Corporation.  All rights reserved.
//   
//    The use and distribution terms for this software are contained in the file
//    named license.txt, which can be found in the root of this distribution.
//    By using this software in any fashion, you are agreeing to be bound by the
//    terms of this license.
//   
//    You must not remove this notice, or any other, from this software.
//   
//
// ==--==
////////////////////////////////////////////////////////////////////////////
//
//  Class:    CultureInfo
//
//
//  Purpose:  This class represents the software preferences of a particular
//            culture or community.  It includes information such as the
//            language, writing system, and a calendar used by the culture
//            as well as methods for common operations such as printing
//            dates and sorting strings.
//
//  Date:     March 31, 1999
//
//
//  !!!! NOTE WHEN CHANGING THIS CLASS !!!!
//
//  If adding or removing members to this class, please update CultureInfoBaseObject
//  in ndp/clr/src/vm/object.h. Note, the "actual" layout of the class may be
//  different than the order in which members are declared. For instance, all
//  reference types will come first in the class before value types (like ints, bools, etc)
//  regardless of the order in which they are declared. The best way to see the
//  actual order of the class is to do a !dumpobj on an instance of the managed
//  object inside of the debugger.
//
////////////////////////////////////////////////////////////////////////////

namespace System.Globalization {
    using System;
    using System.Threading;
    using System.Collections;
    using System.Runtime.CompilerServices;
    using System.Runtime.InteropServices;
    using System.Runtime.Serialization;
    using System.Security.Permissions;
    using System.Reflection;
    using Microsoft.Win32;
    using System.Runtime.Versioning;

    [Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
    public class CultureInfo : ICloneable, IFormatProvider {
        //
        // Special culture IDs
        //
        internal const int zh_CHT_CultureID = 0x7c04;
        // Serbian Neutral culture ID.
        internal const int sr_CultureID = 0x7c1a;
        internal const int sr_SP_Latn_CultureID = 0x081a;

        // Ietf name registry location

        //--------------------------------------------------------------------//
        //                        Internal Information                        //
        //--------------------------------------------------------------------//

        //--------------------------------------------------------------------//
        // Data members to be serialized:
        //--------------------------------------------------------------------//

        // This is the string used to construct CultureInfo.
        // It is in the format of ISO639 (2 letter language name) plus dash plus
        // ISO 3166 (2 letter region name).  The language name is in lowercase and region name
        // are in uppercase. (now part of cultureTableRecord)

        //
        // This is the culture ID used in the NLS+ world.  The concept of cultureID is similar
        // to the concept of LCID in Win32.  However, NLS+ support "neutral" culture
        // which Win32 doesn't support.
        //
        // The format of culture ID (32 bits) is:
        //
        // 31 - 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
        // +-----+ +---------+ +---------------+ +-----------------+
        //    |         |           |            Primary language ID (10 bits)
        //    |         |           +----------- Sublanguage ID (6 its)
        //    |         +----------------------- Sort ID (4 bits)
        //    +--------------------------------- Reserved (12 bits)
        //
        // Primary language ID and sublanguage ID can be zero to specify 'neutral' language.
        // For example, cultureID 0x(0000)0009 is the English neutral culture.
        // cultureID 0x(0000)0000 means the invariant culture (or called neutral culture).
        //
        // We'd just use cultureTableInfo.cultureID for ID, however cultureTableInfo doesn't
        // remember the sort info.

        // WARNING
        // WARNING: All member fields declared here must also be in ndp/clr/src/vm/object.h
        // WARNING: They aren't really private because object.h can access them, but other C# stuff cannot
        // WARNING
        internal int cultureID;
        internal bool m_isReadOnly=false;

        internal CompareInfo compareInfo = null;
        internal TextInfo textInfo = null;
        internal NumberFormatInfo numInfo = null;
        internal DateTimeFormatInfo dateTimeInfo = null;
        internal Calendar calendar = null;

        //
        // The CultureTable instance that we are going to read data from.
        // For supported culture, this will be the CultureTable instance that read data from mscorlib assembly.
        // For customized culture, this will be the CultureTable instance that read data from user customized culture binary file.
        //
        [NonSerialized]internal CultureTableRecord m_cultureTableRecord;
        [NonSerialized]internal bool m_isInherited;
        [NonSerialized]private bool m_isSafeCrossDomain = false;
        [NonSerialized]private int m_createdDomainID = 0;
        [NonSerialized]private CultureInfo m_consoleFallbackCulture = null;

        //

        internal string m_name = null;

        // This will hold the non sorting name to be returned from CultureInfo.Name property.
        // This has a de-DE style name even for de-DE_phoneb type cultures
        [NonSerialized]private string m_nonSortName = null;

        // This will hold the sorting name to be returned from CultureInfo.SortName property.
        // This might be completely unrelated to the culture name if a custom culture.  Ie en-US for fj-FJ.
        // Otherwise its the sort name, ie: de-DE or de-DE_phoneb
        [NonSerialized]private string m_sortName = null;

        // Ietf name
        [NonSerialized]private string m_ietfName = null;

        //--------------------------------------------------------------------//
        //
        // Static data members
        //
        //--------------------------------------------------------------------//

        //Get the current user default culture.  This one is almost always used, so we create it by default.
        private static CultureInfo m_userDefaultCulture   = null;

        //
        // All of the following will be created on demand.
        //

        //The Invariant culture;
        private static CultureInfo m_InvariantCultureInfo = null;

        //The culture used in the user interface. This is mostly used to load correct localized resources.
        private static CultureInfo m_userDefaultUICulture = null;

        //This is the UI culture used to install the OS.
        private static CultureInfo m_InstalledUICultureInfo = null;

        //This is a cache of all previously created cultures.  Valid keys are LCIDs or the name.  We use two hashtables to track them,
        // depending on how they are called.
        private static Hashtable m_LcidCachedCultures = null;
        private static Hashtable m_NameCachedCultures = null;
        private static Hashtable m_IetfCachedCultures = null;

        // May need a registry key if looking up ietf names by name

        //The parent culture.
        [NonSerialized]private CultureInfo m_parent;

        //
        //  Helper Methods.
        //
        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern bool IsValidLCID(int LCID, int flag);

        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern bool IsWin9xInstalledCulture(string cultureKey, int LCID);

        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern unsafe String nativeGetUserDefaultLCID(int* LCID, int lcidType);

        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern unsafe String nativeGetUserDefaultUILanguage(int* LCID);

        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern unsafe String nativeGetSystemDefaultUILanguage(int* LCID);

        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern bool nativeSetThreadLocale(int LCID);

        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern String nativeGetLocaleInfo(int LCID, int field);

        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern int nativeGetCurrentCalendar();

        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern unsafe bool nativeGetDTFIUserValues(int lcid, ref DTFIUserOverrideValues values);

        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern unsafe bool nativeGetNFIUserValues(int lcid, NumberFormatInfo nfi);

        // <SyntheticSupport/>
        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern unsafe bool nativeGetCultureData(int lcid, ref CultureData cultureData);

        // <SyntheticSupport/>
        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern bool nativeEnumSystemLocales(out int [] localesArray);

        // <SyntheticSupport/>
        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern string nativeGetCultureName(int lcid, bool useSNameLCType, bool getMonthName);

        // 
        // Return the path to the Windows directory (such as c:\Windows).  The returned string does NOT include the backslash.
        //
        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern string nativeGetWindowsDirectory();

        //
        // Check if the specified fileName exists in the file system or not.
        //
        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern bool nativeFileExists(String fileName);

        //
        // Get the static int array data used by globalization classes.
        //
        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        internal static extern unsafe int* nativeGetStaticInt32DataTable(int type, out int tableSize);

        internal const int LOCALE_INVARIANT            = 0x007f;
        private  const int LOCALE_NEUTRAL              = 0x0000;
        internal const int LOCALE_USER_DEFAULT         = 0x0400;
        internal const int LOCALE_SYSTEM_DEFAULT       = 0x0800;
        internal const int LOCALE_CUSTOM_DEFAULT       = 0x0c00;
        internal const int LOCALE_CUSTOM_UNSPECIFIED   = 0x1000;
        internal const int LOCALE_TRADITIONAL_SPANISH  = 0x040a;
        internal const int LCID_INSTALLED              = 0x0001;
        internal const int LCID_SUPPORTED              = 0x0002;

        //
        // The CultureTable instance that read data from culture.nlp in the mscorlib assembly.
        //
        static unsafe CultureInfo()
        {

            if (m_InvariantCultureInfo == null) 
            {
                CultureInfo temp = new CultureInfo(LOCALE_INVARIANT, false);
                temp.m_isReadOnly = true;
                m_InvariantCultureInfo = temp;
            }
            // First we set it to Invariant in case someone needs it before we're done finding it.
            // For example, if we throw an exception in InitUserDefaultCulture, we will still need an valid
            // m_userDefaultCulture to be used in Thread.CurrentCulture.
            m_userDefaultCulture = m_userDefaultUICulture = m_InvariantCultureInfo;

            m_userDefaultCulture = InitUserDefaultCulture();
            m_userDefaultUICulture = InitUserDefaultUICulture();

        }

        static unsafe CultureInfo InitUserDefaultCulture()
        {
            int LCID;
            String strDefault = nativeGetUserDefaultLCID(&LCID, LOCALE_USER_DEFAULT);
            CultureInfo temp = GetCultureByLCIDOrName(LCID, strDefault);
            if (temp == null)
            {
                strDefault = nativeGetUserDefaultLCID(&LCID, LOCALE_SYSTEM_DEFAULT);
                temp = GetCultureByLCIDOrName(LCID, strDefault);

                if (temp == null)
                {
                    return (CultureInfo.InvariantCulture);
                }
            }
            temp.m_isReadOnly = true;

            return (temp);
        }

        static unsafe CultureInfo InitUserDefaultUICulture()
        {
            int LCID;
            String strDefault = nativeGetUserDefaultUILanguage(&LCID);
            // In most of cases, UserDefaultCulture == UserDefaultUICulture, so we should use the same instance if possible.
            if (LCID == UserDefaultCulture.LCID || strDefault == UserDefaultCulture.Name)
            {
                return (UserDefaultCulture);
            }

            CultureInfo temp = GetCultureByLCIDOrName(LCID, strDefault);

            if (temp == null)
            {
                strDefault = nativeGetSystemDefaultUILanguage(&LCID);
                temp = GetCultureByLCIDOrName(LCID, strDefault);
            }

            if (temp == null)
            {
                return (CultureInfo.InvariantCulture);
            }

            temp.m_isReadOnly = true;

            return (temp);
        }



        ////////////////////////////////////////////////////////////////////////
        //
        //  CultureInfo Constructors
        //
        ////////////////////////////////////////////////////////////////////////


        public CultureInfo(String name) : this(name, true) {
        }


        public CultureInfo(String name, bool useUserOverride) {
            if (name==null) {
                throw new ArgumentNullException("name",
                    Environment.GetResourceString("ArgumentNull_String"));
            }

            this.m_cultureTableRecord = CultureTableRecord.GetCultureTableRecord(name, useUserOverride);
            this.cultureID = this.m_cultureTableRecord.ActualCultureID;
            this.m_name = this.m_cultureTableRecord.ActualName;
            this.m_isInherited = (this.GetType() != typeof(System.Globalization.CultureInfo));
        }



        public CultureInfo(int culture) : this(culture, true) {
        }


        public unsafe CultureInfo(int culture, bool useUserOverride) {
            // We don't check for other invalid LCIDS here...
            if (culture < 0) {
                throw new ArgumentOutOfRangeException("culture",
                    Environment.GetResourceString("ArgumentOutOfRange_NeedPosNum"));
            }

            switch (culture)
            {
                case LOCALE_CUSTOM_DEFAULT:
                    // CONSDIER: Support this LCID value any time the OS is using a custom culture as the user default.
                    //           Note that if this is to be supported that the code below is not correct since it assumes
                    //           the LCID value is describing the NLS+ culture, not the NLS locale.
/*
                    this.m_cultureTableRecord = CultureInfo.CurrentCulture.m_cultureTableRecord;
                    this.cultureID = CultureInfo.CurrentCulture.cultureID;
                    break;
*/
                case LOCALE_SYSTEM_DEFAULT:
/*
                    String strSystemDefault = nativeGetUserDefaultLCID(&culture, LOCALE_SYSTEM_DEFAULT);
                    CultureInfo systemDefault;

                    // See if we can get our LOCALE_SYSTEM_DEFAULT
                    systemDefault = GetCultureByLCIDOrName(culture, strSystemDefault);

                    if (systemDefault == null)
                        //                                                 
                        systemDefault = InvariantCulture;

                    this.cultureID = systemDefault.cultureID;
                    this.m_cultureTableRecord = systemDefault.m_cultureTableRecord;
                    break;
*/
                case LOCALE_NEUTRAL:
                case LOCALE_USER_DEFAULT:
                case LOCALE_CUSTOM_UNSPECIFIED:
                    // Can't support unknown custom cultures and we do not support neutral or
                    // non-custom user locales.
                    throw new ArgumentException(
                        Environment.GetResourceString("Argument_CultureNotSupported", culture), "culture");
                default:
                    this.cultureID = culture;
                    // Now see if this LCID is supported in the system default culture.nlp table.
                    this.m_cultureTableRecord = CultureTableRecord.GetCultureTableRecord(this.cultureID, useUserOverride);
                    this.m_name = this.m_cultureTableRecord.ActualName;
                    break;
            }
            m_isInherited = (this.GetType() != typeof(System.Globalization.CultureInfo));
        }


        //
        // CheckDomainSafetyObject throw if the object is customized object which cannot be attached to 
        // other object (like CultureInfo or DateTimeFormatInfo).
        //

        internal static void CheckDomainSafetyObject(Object obj, Object container)
        {
            if (obj.GetType().Assembly != typeof(System.Globalization.CultureInfo).Assembly) {
                
                throw new InvalidOperationException(
                            String.Format(
                                CultureInfo.CurrentCulture, 
                                Environment.GetResourceString("InvalidOperation_SubclassedObject"), 
                                obj.GetType(),
                                container.GetType()));
            }
        }

#region Serialization
        // the following fields are defined to keep the compatibility with .NET V1.0/V1.1.
        // don't change/remove the names/types of these fields.
        private int     m_dataItem;
        private bool    m_useUserOverride;

        [OnDeserialized]
        private void OnDeserialized(StreamingContext ctx)
        {
            // In .NET ver 1.0 we can get m_name = null if the Name property never requested 
            // before serializing the culture info object.

            BCLDebug.Assert(m_name != null || cultureID>0,  "[CultureInfo.OnDeserialized] m_name != null || cultureID>0");

            if (m_name != null && cultureID != LOCALE_TRADITIONAL_SPANISH)
                m_cultureTableRecord = CultureTableRecord.GetCultureTableRecord(m_name, m_useUserOverride);
            else
                m_cultureTableRecord = CultureTableRecord.GetCultureTableRecord(cultureID, m_useUserOverride);

            m_isInherited = (this.GetType() != typeof(System.Globalization.CultureInfo));

            if (m_name == null)
            {
                m_name = m_cultureTableRecord.ActualName;
            }

            // in case we have non customized CultureInfo object we shouldn't allow any customized object  
            // to be attached to it for cross app domain safety.
            if (this.GetType().Assembly == typeof(System.Globalization.CultureInfo).Assembly)
            {
                if (textInfo != null)
                {
                    CheckDomainSafetyObject(textInfo, this);
                }
                
                if (compareInfo != null)
                {
                    CheckDomainSafetyObject(compareInfo, this);
                }
            }
        }

        [OnSerializing]
        private void OnSerializing(StreamingContext ctx)
        {
            m_name              = m_cultureTableRecord.CultureName;
            m_useUserOverride   = m_cultureTableRecord.UseUserOverride;
            m_dataItem          = m_cultureTableRecord.EverettDataItem();
        }
#endregion Serialization

        internal bool IsSafeCrossDomain {
            get {
                BCLDebug.Assert(m_createdDomainID != 0, "[CultureInfo.IsSafeCrossDomain] m_createdDomainID != 0");
                return m_isSafeCrossDomain;
            }
        }

        internal int CreatedDomainID {
            get {
                BCLDebug.Assert(m_createdDomainID != 0,  "[CultureInfo.CreatedDomain] m_createdDomainID != 0");
                return m_createdDomainID;
            }
        }
        
        internal void StartCrossDomainTracking() {
        
            // If we have decided about cross domain safety of this instance, we are done
            if (m_createdDomainID != 0)
                return;

            if (this.GetType() == typeof(System.Globalization.CultureInfo))
            {
                m_isSafeCrossDomain = true;
            }
            
            // m_createdDomainID has to be assigned last. We use it to signal that we have
            // completed the check.
            System.Threading.Thread.MemoryBarrier();
            m_createdDomainID = Thread.GetDomainID();
        }

        // Constructor called by SQL Server's special munged culture - creates a culture with
        // a TextInfo and CompareInfo that come from a supplied alternate source. This object
        // is ALWAYS read-only.
        // Note that we really cannot use an LCID version of this override as the cached
        // name we create for it has to include both names, and the logic for this is in
        // the GetCultureInfo override *only*.
        internal CultureInfo(String cultureName, String textAndCompareCultureName)
        {
            if (cultureName==null) {
                throw new ArgumentNullException("cultureName",
                    Environment.GetResourceString("ArgumentNull_String"));
            }

            this.m_cultureTableRecord = CultureTableRecord.GetCultureTableRecord(cultureName, false);
            this.cultureID = this.m_cultureTableRecord.ActualCultureID;
            this.m_name = this.m_cultureTableRecord.ActualName;            

            CultureInfo altCulture = GetCultureInfo(textAndCompareCultureName);

            this.compareInfo = altCulture.CompareInfo;
            this.textInfo = altCulture.TextInfo;
        }


        // Get a culture when trying to create it from LCID or name
        // This happens when asking windows for the locale information.
        // In this case we want to use LCID if provided, otherwise use
        // the name.  Using LCID gives us system default values, using
        // names would allow users to override system cultures when we
        // don't expect them to.
        //
        // Note that this should pick up a CC of the same name for
        // OS ELKS/LIPS/whatever, but will throw if no CC is installed.
        private static CultureInfo GetCultureByLCIDOrName(int preferLCID, String fallbackToString)
        {
            // If we don't have a string or we don't have
            CultureInfo culture = null;

            // We prefer LCID because that gives us the system values, but we can't use
            // it if there's no lang part
            if ((preferLCID & 0x3ff) != 0)
            {
                // Try to get it
                try
                {
                    culture = new CultureInfo(preferLCID);
                }
                catch (ArgumentException)
                {
                }
            }

            if (culture == null && fallbackToString != null && fallbackToString.Length > 0)
            {
                // Try to get it
                try
                {
                    culture = new CultureInfo(fallbackToString);
                }
                catch (ArgumentException)
                {
                }
            }

            return culture;
        }



        public static CultureInfo CreateSpecificCulture(String name) {
            CultureInfo culture;

            try {
                culture = new CultureInfo(name);
            } catch(ArgumentException exp) {
                // When CultureInfo throws this exception, it may be because someone passed the form
                // like "az-az" because it came out of an http accept lang. We should try a little
                // parsing to perhaps fall back to "az" here and use *it* to create the neutral.

                int idx;

                culture = null;
                for(idx = 0; idx < name.Length; idx++) {
                    if('-' == name[idx]) {
                        try {
                            culture = new CultureInfo(name.Substring(0, idx));
                            break;
                        } catch(ArgumentException) {
                            // throw the original exception so the name in the string will be right
                            throw(exp);
                        }
                    }
                }

                if(null == culture) {
                    // nothing to save here; throw the original exception
                    throw(exp);
                }
            }

            //In the most common case, they've given us a specific culture, so we'll just return that.
            if (!(culture.IsNeutralCulture)) {
                return culture;
            }

                int lcid = culture.LCID;
                //If we have the Chinese locale, we have no way of producing a
                //specific culture without encountering significant geopolitical
                //issues.  Based on that, we have no choice but to return.
                if ((lcid & 0x3FF)==0x04) {
                    throw new ArgumentException(Environment.GetResourceString("Argument_NoSpecificCulture"));
                }

            return (new CultureInfo(culture.m_cultureTableRecord.SSPECIFICCULTURE));
        }

        internal static bool VerifyCultureName(CultureInfo culture, bool throwException) {
            BCLDebug.Assert(culture!=null, "[CultureInfo.VerifyCultureName]culture!=null");

            //If we have an instance of one of our CultureInfos, the user can't have changed the
            //name and we know that all names are valid in files.
            if (!culture.m_isInherited) {
                return true;
            }

            // This function is used by ResourceManager.GetResourceFileName(). 
            // ResourceManager searches for resource using CultureInfo.Name,
            // so we should check against CultureInfo.Name.
            String name = culture.Name;

            for (int i=0; i<name.Length; i++) {
                char c = name[i];
                if (Char.IsLetterOrDigit(c) || c=='-' || c=='_') {
                    continue;
                }
                if (throwException) {
                    throw new ArgumentException(Environment.GetResourceString("Argument_InvalidResourceCultureName", name));
                }
                return false;
            }
            return true;
        }

        //--------------------------------------------------------------------//
        //                        Misc static functions                       //
        //--------------------------------------------------------------------//

        internal static int GetSubLangID(int culture)
        {
            return ((culture >> 10) & 0x3f);
        }

        internal static int GetLangID(int culture)
        {
            return (culture & 0xffff);
        }

        internal static int GetSortID(int lcid)
        {
            return ((lcid >> 16) & 0xf);
        }

        ////////////////////////////////////////////////////////////////////////
        //
        //  CurrentCulture
        //
        //  This instance provides methods based on the current user settings.
        //  These settings are volatile and may change over the lifetime of the
        //  thread.
        //
        ////////////////////////////////////////////////////////////////////////


        public static CultureInfo CurrentCulture
        {
            get {
                return Thread.CurrentThread.CurrentCulture;
            }
        }

        //
        // This is the equivalence of the Win32 GetUserDefaultLCID()
        //
        internal static CultureInfo UserDefaultCulture {
            get
            {
                CultureInfo temp = m_userDefaultCulture;
                if (temp == null)
                {
                    //
                    // setting the m_userDefaultCulture with invariant culture before intializing it is a protection
                    // against recursion problem just in case if somebody called CurrentCulture from the CultureInfo
                    // creation path. the recursion can happen if the current user culture is a replaced custom culture.
                    //
                    
                    m_userDefaultCulture = CultureInfo.InvariantCulture;
                    temp = InitUserDefaultCulture();
                    m_userDefaultCulture = temp;
                }
                return (temp);
            }
        }

        //
        //  This is the equivalence of the Win32 GetUserDefaultUILanguage()
        //
        internal static unsafe CultureInfo UserDefaultUICulture {
            get {
                CultureInfo temp = m_userDefaultUICulture;
                if (temp == null) 
                {
                    //
                    // setting the m_userDefaultCulture with invariant culture before intializing it is a protection
                    // against recursion problem just in case if somebody called CurrentUICulture from the CultureInfo
                    // creation path. the recursion can happen if the current user culture is a replaced custom culture.
                    //
                    
                    m_userDefaultUICulture = CultureInfo.InvariantCulture;
                    
                    temp = InitUserDefaultUICulture();
                    m_userDefaultUICulture = temp;
                }
                return (temp);
            }
        }


        public static CultureInfo CurrentUICulture {
            get {
                return Thread.CurrentThread.CurrentUICulture;
            }
        }


        //
        // This is the equivalence of the Win32 GetSystemDefaultUILanguage()
        //
        public static unsafe CultureInfo InstalledUICulture {
            get {
                CultureInfo temp = m_InstalledUICultureInfo;
                if (temp == null) {
                    int LCID;
                    String strDefault = nativeGetSystemDefaultUILanguage(&LCID);
                    temp = GetCultureByLCIDOrName(LCID, strDefault);

                    if (temp == null)
                    {
                        temp = new CultureInfo(LOCALE_INVARIANT, true);
                    }

                    temp.m_isReadOnly = true;
                    m_InstalledUICultureInfo = temp;
                }
                return (temp);
            }
        }

        ////////////////////////////////////////////////////////////////////////
        //
        //  InvariantCulture
        //
        //  This instance provides methods, for example for casing and sorting,
        //  that are independent of the system and current user settings.  It
        //  should be used only by processes such as some system services that
        //  require such invariant results (eg. file systems).  In general,
        //  the results are not linguistically correct and do not match any
        //  culture info.
        //
        ////////////////////////////////////////////////////////////////////////


        public static CultureInfo InvariantCulture {
            get {
                return (m_InvariantCultureInfo);
            }
        }


        ////////////////////////////////////////////////////////////////////////
        //
        //  Parent
        //
        //  Return the parent CultureInfo for the current instance.
        //
        ////////////////////////////////////////////////////////////////////////

        public virtual CultureInfo Parent
        {
            get
            {
                if (null == m_parent)
                {
                    try
                    {
                        int parentCulture = this.m_cultureTableRecord.IPARENT;
                        if (parentCulture == LOCALE_INVARIANT)
                        {
                            m_parent = InvariantCulture;
                        }
                        else if (CultureTableRecord.IsCustomCultureId(parentCulture)) {
                            // Customized culture -- use the string for the parent.
                            m_parent = new CultureInfo(this.m_cultureTableRecord.SPARENT);
                        }
                        else
                        {
                            m_parent = new CultureInfo(parentCulture, this.m_cultureTableRecord.UseUserOverride);
                        }
                    }
                    catch (ArgumentException)
                    {
                        // For whatever reason our IPARENT or SPARENT wasn't correct, so use invariant
                        // We can't allow ourselves to fail.  In case of custom cultures the parent of the
                        // current custom culture isn't installed.
                        m_parent =  InvariantCulture;
                    }
                }
                return m_parent;
            }
        }

        ////////////////////////////////////////////////////////////////////////
        //
        //  LCID
        //
        //  Returns a properly formed culture identifier for the current
        //  culture info.
        //
        ////////////////////////////////////////////////////////////////////////


        public virtual int LCID {
            get {
                return (this.cultureID);
            }
        }

        ////////////////////////////////////////////////////////////////////////
        //
        //  BaseInputLanguage
        //
        //  Essentially an LCID, though one that may be different than LCID in the case
        //  of a customized culture (LCID == -1).
        //
        ////////////////////////////////////////////////////////////////////////

        [System.Runtime.InteropServices.ComVisible(false)]
        public virtual int KeyboardLayoutId
        {
            get
            {
                int keyId = this.m_cultureTableRecord.IINPUTLANGUAGEHANDLE;

                // Not a customized culture, return the default Keyboard layout ID, which is the same as the language ID.
                return (keyId);
            }
        }


        public static CultureInfo[] GetCultures(CultureTypes types) {
            return (CultureTable.Default.GetCultures(types));
        }


        ////////////////////////////////////////////////////////////////////////
        //
        //  Name
        //
        //  Returns the full name of the CultureInfo. The name is in format like
        //  "en-US"  This version does NOT include sort information in the name.
        //
        ////////////////////////////////////////////////////////////////////////
        public virtual String Name {
            get {
                // We return non sorting name here.
                if (this.m_nonSortName == null) {
                    this.m_nonSortName  = this.m_cultureTableRecord.CultureName;
                }
                return this.m_nonSortName;
            }
        }


        internal String SortName
        {
            get
            {
                if (this.m_sortName == null)
                {
                    if (CultureTableRecord.IsCustomCultureId(cultureID))
                    {
                        CultureInfo sortCI = CultureInfo.GetCultureInfo(CompareInfoId);

                        BCLDebug.Assert(!CultureTableRecord.IsCustomCultureId(sortCI.cultureID),
                                        "[CultureInfo.SortName]Expected non-custom sort id");

                        if (CultureTableRecord.IsCustomCultureId(sortCI.cultureID))
                        {
                            // m_name create could call SortName (not supposed to for CI),
                            // but just to be safe, use SNAME not m_name
                            this.m_sortName = m_cultureTableRecord.SNAME;
                        }
                        else
                        {
                            this.m_sortName = sortCI.SortName;  // Name of culture doing our sort
                        }
                    }
                    else
                    {
                        // If its not custom, our sort is our full name
                        BCLDebug.Assert(m_name != null, "[CultureInfo.SortName]Always expect m_name to be set");
                        this.m_sortName = this.m_name;          // full name, including sort
                    }
                }
                return this.m_sortName;
            }
        }

        [System.Runtime.InteropServices.ComVisible(false)]
        public String IetfLanguageTag
        {
            get
            {
                if (this.m_ietfName == null)
                {
                    this.m_ietfName = this.m_cultureTableRecord.SIETFTAG;
                }

                // IETF RFC 3066 name goes here
                return this.m_ietfName;
            }
        }

        ////////////////////////////////////////////////////////////////////////
        //
        //  DisplayName
        //
        //  Returns the full name of the CultureInfo in the localized language.
        //  For example, if the localized language of the runtime is Spanish and the CultureInfo is
        //  US English, "Ingles (Estados Unidos)" will be returned.
        //
        ////////////////////////////////////////////////////////////////////////


        public virtual String DisplayName
        {
            get
            {
                BCLDebug.Assert(m_name != null, "[CultureInfo.DisplayName]Always expect m_name to be set");
                
                if (m_cultureTableRecord.IsCustomCulture)
                {
                    if (m_cultureTableRecord.IsReplacementCulture)
                    {
                        // <SyntheticSupport/>
                        if (m_cultureTableRecord.IsSynthetic)
                            return m_cultureTableRecord.CultureNativeDisplayName;
                        else
                            return (Environment.GetResourceString("Globalization.ci_" + this.m_name));
                    }
                    else
                    {
                        return m_cultureTableRecord.SNATIVEDISPLAYNAME;
                    }
                }
                else
                {
                    // <SyntheticSupport/>
                    if (m_cultureTableRecord.IsSynthetic)
                        return m_cultureTableRecord.CultureNativeDisplayName;
                    else
                        return (Environment.GetResourceString("Globalization.ci_" + this.m_name));
                }
            }
        }

        ////////////////////////////////////////////////////////////////////////
        //
        //  GetNativeName
        //
        //  Returns the full name of the CultureInfo in the native language.
        //  For example, if the CultureInfo is US English, "English
        //  (United States)" will be returned.
        //
        ////////////////////////////////////////////////////////////////////////


        public virtual String NativeName {
            get {
                return (this.m_cultureTableRecord.SNATIVEDISPLAYNAME);
            }
        }

        ////////////////////////////////////////////////////////////////////////
        //
        //  GetEnglishName
        //
        //  Returns the full name of the CultureInfo in English.
        //  For example, if the CultureInfo is US English, "English
        //  (United States)" will be returned.
        //
        ////////////////////////////////////////////////////////////////////////


        public virtual String EnglishName {
            get {
                return (this.m_cultureTableRecord.SENGDISPLAYNAME);
            }
        }


        public virtual String TwoLetterISOLanguageName {
            get {
                return (this.m_cultureTableRecord.SISO639LANGNAME);
            }
        }


        public virtual String ThreeLetterISOLanguageName {
            get {
                return (this.m_cultureTableRecord.SISO639LANGNAME2);
            }
        }

        ////////////////////////////////////////////////////////////////////////
        //
        //  GetAbbreviatedName
        //
        //  Returns the abbreviated name for the current instance.  The
        //  abbreviated form is usually based on the ISO 639 standard, for
        //  example the two letter abbreviation for English is "en".
        //
        ////////////////////////////////////////////////////////////////////////


       public virtual String ThreeLetterWindowsLanguageName {
            get {
                return (this.m_cultureTableRecord.SABBREVLANGNAME);
            }
        }

        ////////////////////////////////////////////////////////////////////////
        //
        //  CompareInfo               Read-Only Property
        //
        //  Gets the CompareInfo for this culture.
        //
        ////////////////////////////////////////////////////////////////////////


        public virtual CompareInfo CompareInfo {
            get {
                if (compareInfo==null) {

                    CompareInfo temp;

                    
                    if (IsNeutralCulture && !CultureTableRecord.IsCustomCultureId(cultureID))
                        temp = CompareInfo.GetCompareInfo(cultureID);
                    else
                        temp = CompareInfo.GetCompareInfo(CompareInfoId);

                    // The name is not preset when CompareInfo is set by LCID, so lets set it now.
                    temp.SetName(this.SortName);
                    compareInfo = temp;

                }
                return (compareInfo);
            }
        }

        internal int CompareInfoId {
            get {
                int compareId;

                if (this.cultureID == LOCALE_TRADITIONAL_SPANISH) {
                    // Special case Trad. Spanish since there is no 
                    // ICOMPAREINFO entry for them.
                    compareId = LOCALE_TRADITIONAL_SPANISH;
                } else if (GetSortID(this.cultureID) != 0) {
                    // Special case alternate sorts since there is no 
                    // ICOMPAREINFO entry for them.
                    compareId = this.cultureID;
                } else {
                    compareId = unchecked((int)this.m_cultureTableRecord.ICOMPAREINFO);
                }

                return compareId;
            }
        }

        ////////////////////////////////////////////////////////////////////////
        //
        //  TextInfo
        //
        //  Gets the TextInfo for this culture.
        //
        ////////////////////////////////////////////////////////////////////////


        public virtual TextInfo TextInfo {
            get {
                if (textInfo==null) {
                    // Make a new textInfo
                    TextInfo tempTextInfo = new TextInfo(this.m_cultureTableRecord);
                    tempTextInfo.SetReadOnlyState(m_isReadOnly);
                    textInfo = tempTextInfo;
                }
                return (textInfo);
            }
        }

        ////////////////////////////////////////////////////////////////////////
        //
        //  Equals
        //
        //  Implements Object.Equals().  Returns a boolean indicating whether
        //  or not object refers to the same CultureInfo as the current instance.
        //
        ////////////////////////////////////////////////////////////////////////


        public override bool Equals(Object value)
        {
            if (Object.ReferenceEquals(this, value))
                return true;

            CultureInfo that = value as CultureInfo;

            if (that != null)
            {
                // using CompareInfo to verify the data passed through the constructor
                // CultureInfo(String cultureName, String textAndCompareCultureName)

                return (this.Name.Equals(that.Name) && this.CompareInfo.Equals(that.CompareInfo));
            }

            return (false);
        }


        ////////////////////////////////////////////////////////////////////////
        //
        //  GetHashCode
        //
        //  Implements Object.GetHashCode().  Returns the hash code for the
        //  CultureInfo.  The hash code is guaranteed to be the same for CultureInfo A
        //  and B where A.Equals(B) is true.
        //
        ////////////////////////////////////////////////////////////////////////


        public override int GetHashCode()
        {
            return (this.Name.GetHashCode() + this.CompareInfo.GetHashCode());
        }


        ////////////////////////////////////////////////////////////////////////
        //
        //  ToString
        //
        //  Implements Object.ToString().  Returns the name of the CultureInfo,
        //  eg. "English (United States)".
        //
        ////////////////////////////////////////////////////////////////////////


        public override String ToString()
        {
            BCLDebug.Assert(m_name != null, "[CultureInfo.ToString]Always expect m_name to be set");
            return m_name;
        }


        public virtual Object GetFormat(Type formatType) {
            if (formatType == typeof(NumberFormatInfo)) {
                return (NumberFormat);
            }
            if (formatType == typeof(DateTimeFormatInfo)) {
                return (DateTimeFormat);
            }
            return (null);
        }

        internal static void CheckNeutral(CultureInfo culture) {
            if (culture.IsNeutralCulture) {
                    BCLDebug.Assert(culture.m_name != null, "[CultureInfo.CheckNeutral]Always expect m_name to be set");
                    throw new NotSupportedException(
                                    Environment.GetResourceString("Argument_CultureInvalidFormat",
                                    culture.m_name));
            }
        }

        public virtual bool IsNeutralCulture {
            get {
                return this.m_cultureTableRecord.IsNeutralCulture;
            }
        }

        [System.Runtime.InteropServices.ComVisible(false)]
        public CultureTypes CultureTypes
        {
            get
            {
                CultureTypes types = 0;

                if (m_cultureTableRecord.IsNeutralCulture)
                    types |= CultureTypes.NeutralCultures;
                else 
                    types |= CultureTypes.SpecificCultures;

                if (m_cultureTableRecord.IsSynthetic)
                    types |= CultureTypes.WindowsOnlyCultures | CultureTypes.InstalledWin32Cultures; // Synthetic is installed culture too.
                else
                {
                    // Not Synthetic
                    if (CultureTable.IsInstalledLCID(cultureID)) 
                        types |= CultureTypes.InstalledWin32Cultures;
                        
                    if (!m_cultureTableRecord.IsCustomCulture || m_cultureTableRecord.IsReplacementCulture)
                        types |= CultureTypes.FrameworkCultures;
                }

                if (m_cultureTableRecord.IsCustomCulture)
                {
                    types |= CultureTypes.UserCustomCulture;

                    if (m_cultureTableRecord.IsReplacementCulture)
                        types |= CultureTypes.ReplacementCultures;
                }


                return types;
            }
        }

        public virtual NumberFormatInfo NumberFormat {
            get {
                CultureInfo.CheckNeutral(this);
                if (numInfo == null) {
                    NumberFormatInfo temp = new NumberFormatInfo(this.m_cultureTableRecord);
                    temp.isReadOnly = m_isReadOnly;
                    numInfo = temp;
                }
                return (numInfo);
            }
            set {
                VerifyWritable();
                if (value == null) {
                    throw new ArgumentNullException("value",
                        Environment.GetResourceString("ArgumentNull_Obj"));
                }
                numInfo = value;
            }
        }

        ////////////////////////////////////////////////////////////////////////
        //
        // GetDateTimeFormatInfo
        //
        // Create a DateTimeFormatInfo, and fill in the properties according to
        // the CultureID.
        //
        ////////////////////////////////////////////////////////////////////////


        public virtual DateTimeFormatInfo DateTimeFormat {
            get {
                if (dateTimeInfo == null) {
                    CultureInfo.CheckNeutral(this);
                    // Change the calendar of DTFI to the specified calendar of this CultureInfo.
                    DateTimeFormatInfo temp = new DateTimeFormatInfo(
                        this.m_cultureTableRecord, GetLangID(cultureID), this.Calendar);
                    temp.m_isReadOnly = m_isReadOnly;
                    System.Threading.Thread.MemoryBarrier();
                    dateTimeInfo = temp;
                }
                return (dateTimeInfo);
            }

            set {
                VerifyWritable();
                if (value == null) {
                    throw new ArgumentNullException("value",
                        Environment.GetResourceString("ArgumentNull_Obj"));
                }
                dateTimeInfo = value;
            }
        }



        public unsafe void ClearCachedData() {
            m_userDefaultUICulture = null;
            m_userDefaultCulture = null;

            RegionInfo.m_currentRegionInfo = null;

            TimeZone.ResetTimeZone();

            // Delete the cached cultures.
            m_LcidCachedCultures = null;
            m_NameCachedCultures = null;
            m_IetfCachedCultures = null;

            CultureTableRecord.ResetCustomCulturesCache();
            CompareInfo.ClearDefaultAssemblyCache();
        }

        /*=================================GetCalendarInstance==========================
        **Action: Map a Win32 CALID to an instance of supported calendar.
        **Returns: An instance of calendar.
        **Arguments: calType    The Win32 CALID
        **Exceptions:
        **      Shouldn't throw exception since the calType value is from our data table or from Win32 registry.
        **      If we are in trouble (like getting a weird value from Win32 registry), just return the GregorianCalendar.
        ============================================================================*/
        internal static Calendar GetCalendarInstance(int calType) {
            if (calType==Calendar.CAL_GREGORIAN) {
                return (new GregorianCalendar());
            }
            return GetCalendarInstanceRare(calType);
        }

        //This function exists as a shortcut to prevent us from loading all of the non-gregorian
        //calendars unless they're required.
        internal static Calendar GetCalendarInstanceRare(int calType) {
            BCLDebug.Assert(calType!=Calendar.CAL_GREGORIAN, "calType!=Calendar.CAL_GREGORIAN");

            switch (calType) {
                case Calendar.CAL_GREGORIAN_US:               // Gregorian (U.S.) calendar
                case Calendar.CAL_GREGORIAN_ME_FRENCH:        // Gregorian Middle East French calendar
                case Calendar.CAL_GREGORIAN_ARABIC:           // Gregorian Arabic calendar
                case Calendar.CAL_GREGORIAN_XLIT_ENGLISH:     // Gregorian Transliterated English calendar
                case Calendar.CAL_GREGORIAN_XLIT_FRENCH:      // Gregorian Transliterated French calendar
                    return (new GregorianCalendar((GregorianCalendarTypes)calType));
                case Calendar.CAL_TAIWAN:                     // Taiwan Era calendar
                    return (new TaiwanCalendar());
                case Calendar.CAL_JAPAN:                      // Japanese Emperor Era calendar
                    return (new JapaneseCalendar());
                case Calendar.CAL_KOREA:                      // Korean Tangun Era calendar
                    return (new KoreanCalendar());
                case Calendar.CAL_HIJRI:                      // Hijri (Arabic Lunar) calendar
                    return (new HijriCalendar());
                case Calendar.CAL_THAI:                       // Thai calendar
                    return (new ThaiBuddhistCalendar());
                case Calendar.CAL_HEBREW:                     // Hebrew (Lunar) calendar
                    return (new HebrewCalendar());
                case Calendar.CAL_PERSIAN:
                    return (new PersianCalendar());
                case Calendar.CAL_UMALQURA:
                    return (new UmAlQuraCalendar());
                case Calendar.CAL_CHINESELUNISOLAR:
                    return (new ChineseLunisolarCalendar());
                case Calendar.CAL_JAPANESELUNISOLAR:
                    return (new JapaneseLunisolarCalendar());
                case Calendar.CAL_KOREANLUNISOLAR:
                    return (new KoreanLunisolarCalendar());
                case Calendar.CAL_TAIWANLUNISOLAR:
                    return (new TaiwanLunisolarCalendar());
            }
            return (new GregorianCalendar());
        }


        /*=================================Calendar==========================
        **Action: Return/set the default calendar used by this culture.
        ** This value can be overridden by regional option if this is a current culture.
        **Returns:
        **Arguments:
        **Exceptions:
        **  ArgumentNull_Obj if the set value is null.
        ============================================================================*/


        public virtual Calendar Calendar {
            get {
                if (calendar == null) {
                    BCLDebug.Assert(this.m_cultureTableRecord.IOPTIONALCALENDARS.Length > 0, "this.m_cultureTableRecord.IOPTIONALCALENDARS.Length > 0");
                    // Get the default calendar for this culture.  Note that the value can be
                    // from registry if this is a user default culture.
                    int calType = this.m_cultureTableRecord.ICALENDARTYPE;

                    Calendar newObj = GetCalendarInstance(calType);
                    System.Threading.Thread.MemoryBarrier();
                    newObj.SetReadOnlyState(m_isReadOnly);
                    calendar = newObj;
                }
                return (calendar);
            }
        }

        /*=================================OptionCalendars==========================
        **Action: Return an array of the optional calendar for this culture.
        **Returns: an array of Calendar.
        **Arguments:
        **Exceptions:
        ============================================================================*/


        public virtual Calendar[] OptionalCalendars {
            get {
                //
                // This property always returns a new copy of the calendar array.
                //
                int[] calID = this.m_cultureTableRecord.IOPTIONALCALENDARS;
                Calendar [] cals = new Calendar[calID.Length];
                for (int i = 0; i < cals.Length; i++) {
                    cals[i] = GetCalendarInstance(calID[i]);
                }
                return (cals);
            }
        }


        public bool UseUserOverride {
            get {
                return (this.m_cultureTableRecord.UseUserOverride);
            }
        }

        [System.Runtime.InteropServices.ComVisible(false)]
        public CultureInfo GetConsoleFallbackUICulture()
        {
            CultureInfo temp = m_consoleFallbackCulture;
            if (temp == null)
            {
                temp = GetCultureInfo(this.m_cultureTableRecord.SCONSOLEFALLBACKNAME);
                temp.m_isReadOnly = true;
                m_consoleFallbackCulture = temp;
            }
            return (temp);
        }


        public virtual Object Clone()
        {
            CultureInfo ci = (CultureInfo)MemberwiseClone();
            ci.m_isReadOnly = false;

            if (!ci.IsNeutralCulture)
            {
                //If this is exactly our type, we can make certain optimizations so that we don't allocate NumberFormatInfo or DTFI unless
                //they've already been allocated.  If this is a derived type, we'll take a more generic codepath.
                if (!m_isInherited) 
                {
                    if (dateTimeInfo != null) {
                        ci.dateTimeInfo = (DateTimeFormatInfo)dateTimeInfo.Clone();
                    }
                    if (numInfo != null) {
                        ci.numInfo = (NumberFormatInfo)numInfo.Clone();
                    }

                } else {
                    ci.DateTimeFormat = (DateTimeFormatInfo)this.DateTimeFormat.Clone();
                    ci.NumberFormat   = (NumberFormatInfo)this.NumberFormat.Clone();
                }
            }

            if (textInfo != null)
            {
                ci.textInfo = (TextInfo) textInfo.Clone();
            }

            if (calendar != null)
            {
                ci.calendar = (Calendar) calendar.Clone();
            }

            return (ci);
        }


        public static CultureInfo ReadOnly(CultureInfo ci) {
            if (ci == null) {
                throw new ArgumentNullException("ci");
            }
            if (ci.IsReadOnly) {
                return (ci);
            }
            CultureInfo info = (CultureInfo)(ci.MemberwiseClone());

            if (!ci.IsNeutralCulture)
            {
                //If this is exactly our type, we can make certain optimizations so that we don't allocate NumberFormatInfo or DTFI unless
                //they've already been allocated.  If this is a derived type, we'll take a more generic codepath.
                if (!ci.m_isInherited) {
                    if (ci.dateTimeInfo != null) {
                        info.dateTimeInfo = DateTimeFormatInfo.ReadOnly(ci.dateTimeInfo);
                    }
                    if (ci.numInfo != null) {
                        info.numInfo = NumberFormatInfo.ReadOnly(ci.numInfo);
                    }

                } else {
                    info.DateTimeFormat = DateTimeFormatInfo.ReadOnly(ci.DateTimeFormat);
                    info.NumberFormat = NumberFormatInfo.ReadOnly(ci.NumberFormat);
                }
            }
            
            if (ci.textInfo != null)
            {
                info.textInfo = TextInfo.ReadOnly(ci.textInfo);
            }

            if (ci.calendar != null)
            {
                info.calendar = Calendar.ReadOnly(ci.calendar);
            }

            // Don't set the read-only flag too early.
            // We should set the read-only flag here.  Otherwise, info.DateTimeFormat will not be able to set.
            info.m_isReadOnly = true;

            return (info);
        }


        public bool IsReadOnly {
            get {
                return (m_isReadOnly);
            }
        }

        private void VerifyWritable() {
            if (m_isReadOnly) {
                throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_ReadOnly"));
            }
        }

        // Helper function both both overloads of GetCachedReadOnlyCulture.  If lcid is 0, we use the name.
        // If lcid is -1, use the altName and create one of those special SQL cultures.
        // If lcid is -2 we're looking for Ietf name
        internal static CultureInfo GetCultureInfoHelper(int lcid, string name, string altName)
        {
            // retval is our return value.
            CultureInfo retval;

            // Temporary hashtable for the names.
            Hashtable tempNameHT = m_NameCachedCultures;

            if (name != null)
                name = CultureTableRecord.AnsiToLower(name);
            
            if (altName != null)
                altName = CultureTableRecord.AnsiToLower(altName);

            // We expect the same result for all 3 hashtables, but will test individually for added safety.
            if (tempNameHT == null)
            {
                tempNameHT = new Hashtable();
            }
            else
            {
                // If we are called by name, check if the object exists in the hashtable.  If so, return it.
                if (lcid == -1)
                {
                    retval = (CultureInfo) tempNameHT[name + '\xfffd' + altName];
                    if (retval != null)
                    {
                        return retval;
                    }
                }
                else if (lcid == 0)
                {
                    retval = (CultureInfo) tempNameHT[name];
                    if (retval != null)
                    {
                        return retval;
                    }
                }
            }

            // Next, the Lcid table.
            Hashtable tempLcidHT = m_LcidCachedCultures;

            if (tempLcidHT == null)
            {
                // Case insensitive is not an issue here, save the constructor call.
                tempLcidHT = new Hashtable();
            }
            else
            {
                // If we were called by Lcid, check if the object exists in the table.  If so, return it.
                if (lcid > 0)
                {
                    retval = (CultureInfo) tempLcidHT[lcid];
                    if (retval != null)
                    {
                        return retval;
                    }
                }
            }

            // Last the Ietf name table
            Hashtable tempIetfHT = m_IetfCachedCultures;

            if (tempIetfHT == null)
            {
                tempIetfHT = new Hashtable();
            }
            else
            {
                // If we wanted ietf name, then lcid is -2
                if (lcid == -2)
                {
                    retval = (CultureInfo)tempIetfHT[name];
                    if (retval != null)
                    {
                        return retval;
                    }
                }
            }

            // We now have two temporary hashtables and the desired object was not found.
            // We'll construct it.  We catch any exceptions from the constructor call and return null.
            try
            {
                switch(lcid)
                {
                    case -2:
                    {
                        // -2 is Ietf name, map Ietf name to Culture name and get it by name
                        String cultureName = CultureTableRecord.GetCultureNameFromIetfName(name);
                        if (cultureName == null)
                            return null;
                        retval = new CultureInfo(cultureName, false);
                        break;
                    }

                    case -1:
                        // call the private constructor
                        retval = new CultureInfo(name, altName);
                        break;

                    case 0:
                        retval = new CultureInfo(name, false);
                        break;

                    default:
                        
                        //
                        // checking the current culture first is a protection against recursion so the creation
                        // code of CompareInfo is calling GetCultureInfo.
                        // The recursion can happen if we have current user culture is replaced custom culture
                        // and we are trying to create object for that culture and current user culture is not
                        // stored in our cache.
                        //
                        
                        if (m_userDefaultCulture != null && m_userDefaultCulture.LCID == lcid)
                        {
                            retval = (CultureInfo) m_userDefaultCulture.Clone();
                            retval.m_cultureTableRecord = retval.m_cultureTableRecord.CloneWithUserOverride(false);
                        }
                        else
                        {
                            retval = new CultureInfo(lcid, false);
                        }
                        break;
                }
            }
            catch(ArgumentException)
            {
                return null;
            }

            // Set it to read-only
            retval.m_isReadOnly = true;

            if (lcid == -1)
            {
                // This new culture will be added only to the name hash table.
                tempNameHT[name + '\xfffd' + altName] = retval;

                // when lcid == -1 then TextInfo object is already get created and we need to set it as read only.
                retval.TextInfo.SetReadOnlyState(true);
            }
            else
            {
                // We add this new culture info object to all 3 hash tables.
                tempLcidHT[retval.LCID] = retval;

                string newName = CultureTableRecord.AnsiToLower(retval.m_name);
                
                tempNameHT[newName] = retval;

                newName = retval.IetfLanguageTag;
                if (newName != null)
                {
                    newName = CultureTableRecord.AnsiToLower(newName);
                    tempIetfHT[newName] = retval;
                }

                if (lcid == -2 && !name.Equals(newName))
                    tempIetfHT[name] = retval;
                
            }

            // Copy the two hashtables to the corresponding member variables.  This will potentially overwrite
            // new tables simultaneously created by a new thread, but maximizes thread safety.
            // If it was funky name we don't need to cache Ietf or LCID names.
            if(-1 != lcid)
            {
                // Only when we modify the lcid hash table, is there a need to overwrite.
                m_LcidCachedCultures = tempLcidHT;
                m_IetfCachedCultures = tempIetfHT;
            }

            m_NameCachedCultures = tempNameHT;

            // Finally, return our new CultureInfo object.
            return retval;
        }

        // Gets a cached copy of the specified culture from an internal hashtable (or creates it
        // if not found).
        public static CultureInfo GetCultureInfo(int culture)
        {
            // Must check for -1 now since the helper function uses the value to signal
            // the altCulture code path for SQL Server.
            // Also check for zero as this would fail trying to add as a key to the hash.
            if (culture <= 0) {
                throw new ArgumentOutOfRangeException("culture",
                    Environment.GetResourceString("ArgumentOutOfRange_NeedPosNum"));
            }

            CultureInfo retval = GetCultureInfoHelper(culture, null, null);
            if (null == retval)
            {
                throw new ArgumentException(
                    Environment.GetResourceString("Argument_CultureNotSupported", culture), "culture");
            }
            return retval;

        }

        // Gets a cached copy of the specified culture from an internal hashtable (or creates it
        // if not found).
        public static CultureInfo GetCultureInfo(string name)
        {
            // Make sure we have a valid, non-zero length string as name
            if (name == null)
            {
                throw new ArgumentNullException("name");
            }

            CultureInfo retval = GetCultureInfoHelper(0, name, null);
            if (retval == null)
            {
                throw new ArgumentException(
                                String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("Argument_InvalidCultureName"), name),
                                "name");
            }
            return retval;
        }

        // Gets a cached copy of the specified culture from an internal hashtable (or creates it
        // if not found).
        public static CultureInfo GetCultureInfo(string name, string altName)
        {
            // Make sure we have a valid, non-zero length string as name
            if (null == name)
            {
                throw new ArgumentNullException("name");
            }

            if (null == altName)
            {
                throw new ArgumentNullException("altName");
            }

            CultureInfo retval = GetCultureInfoHelper(-1, name, altName);
            if (retval == null)
            {
                throw new ArgumentException(
                                String.Format(
                                    CultureInfo.CurrentCulture, 
                                    Environment.GetResourceString("Argument_OneOfCulturesNotSupported"), 
                                    name,
                                    altName),
                                "name");
            }
            return retval;
        }

        // Get a cached copy of the specified culture from ietf language tag.
        public static CultureInfo GetCultureInfoByIetfLanguageTag(string name)
        {
            // Make sure we have a valid, non-zero length string as name
            if (null == name)
            {
                throw new ArgumentNullException("name");
            }

            CultureInfo retval = GetCultureInfoHelper(-2, name, null);
            if (null == retval)
            {
                throw new ArgumentException(
                                String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString(
                                    "Argument_CultureIetfNotSupported"), name),
                                    "name");
            }

            return retval;
        }

        // Looks for Ietf names in the registry.
    }
}

